// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "helper.h"  // NOLINT

// #define DEBUG_STEP

// 根据上一步计算出的可以复原的query_id进行状态恢复
__global__ void speculate_recover_block(int *recover_block_list,  // [bsz]
                                        int *recover_len,
                                        bool *stop_flags,
                                        int *seq_lens_this_time,
                                        int *ori_seq_lens_encoder,
                                        int *ori_seq_lens_decoder,
                                        int *seq_lens_encoder,
                                        int *seq_lens_decoder,
                                        int *block_tables,
                                        int *free_list,
                                        int *free_list_len,
                                        int64_t *input_ids,
                                        int64_t *pre_ids,
                                        int64_t *step_idx,
                                        int *encoder_block_lens,
                                        int *used_list_len,
                                        const int64_t *next_tokens,
                                        const int64_t *first_token_ids,
                                        const int bsz,
                                        const int block_num_per_seq,
                                        const int length,
                                        const int pre_id_length) {
    const int bid = blockIdx.x;
    const int tid = threadIdx.x;
    __shared__ int ori_free_list_len;
    if (bid < recover_len[0]) {
        const int recover_id = recover_block_list[bid];
        const int ori_seq_len_encoder = ori_seq_lens_encoder[recover_id];
        const int step_idx_now = step_idx[recover_id];
        const int seq_len = ori_seq_len_encoder + step_idx_now;
        const int encoder_block_len = encoder_block_lens[recover_id];
        const int decoder_used_len = used_list_len[recover_id];
        int *block_table_now = block_tables + recover_id * block_num_per_seq;
        int64_t *input_ids_now = input_ids + recover_id * length;
        int64_t *pre_ids_now = pre_ids + recover_id * pre_id_length;
        if (tid == 0) {
            seq_lens_this_time[recover_id] = seq_len;
            seq_lens_encoder[recover_id] = seq_len;
            seq_lens_decoder[recover_id] = ori_seq_lens_decoder[recover_id];
            stop_flags[recover_id] = false;
            // input_ids_now[ori_seq_len_encoder + step_idx_now - 1] =
            //     next_tokens[recover_id];  // next tokens
            input_ids_now[0] =
                first_token_ids[recover_id];  // set first prompt token
            const int ori_free_list_len_tid0 =
                atomicSub(free_list_len, decoder_used_len);
            ori_free_list_len = ori_free_list_len_tid0;
#ifdef DEBUG_STEP
            printf(
                "seq_id: %d, ori_seq_len_encoder: %d, step_idx_now: %d, "
                "seq_len: %d, ori_free_list_len_tid0: %d, "
                "ori_free_list_len: %d\n",
                recover_id,
                ori_seq_len_encoder,
                step_idx_now,
                seq_len,
                ori_free_list_len_tid0,
                ori_free_list_len);
#endif
        }
        __syncthreads();
        // 恢复block table
        for (int i = tid; i < decoder_used_len; i += blockDim.x) {
            block_table_now[encoder_block_len + i] =
                free_list[ori_free_list_len - i - 1];
        }
        // 恢复input_ids
        for (int i = tid; i < step_idx_now; i += blockDim.x) {
            input_ids_now[ori_seq_len_encoder + i] = pre_ids_now[i + 1];
        }
    }

    if (bid == 0 && tid == 0) {
        recover_len[0] = 0;
    }
}

void SpeculateStepPaddle(
    const paddle::Tensor &stop_flags,
    const paddle::Tensor &seq_lens_this_time,
    const paddle::Tensor &ori_seq_lens_encoder,
    const paddle::Tensor &ori_seq_lens_decoder,
    const paddle::Tensor &seq_lens_encoder,
    const paddle::Tensor &seq_lens_decoder,
    const paddle::Tensor &block_tables,  // [bsz, block_num_per_seq]
    const paddle::Tensor &encoder_block_lens,
    const paddle::Tensor &is_block_step,
    const paddle::Tensor &step_block_list,
    const paddle::Tensor &step_lens,
    const paddle::Tensor &recover_block_list,
    const paddle::Tensor &recover_lens,
    const paddle::Tensor &need_block_list,
    const paddle::Tensor &need_block_len,
    const paddle::Tensor &used_list_len,
    const paddle::Tensor &free_list,
    const paddle::Tensor &free_list_len,
    const paddle::Tensor &input_ids,
    const paddle::Tensor &pre_ids,
    const paddle::Tensor &step_idx,
    const paddle::Tensor &next_tokens,
    const paddle::Tensor &first_token_ids,
    const paddle::Tensor &accept_num,
    const int block_size,
    const int encoder_decoder_block_num,
    const int max_draft_tokens) {
    auto cu_stream = seq_lens_this_time.stream();
    const int bsz = seq_lens_this_time.shape()[0];
    const int block_num_per_seq = block_tables.shape()[1];
    const int length = input_ids.shape()[1];
    const int pre_id_length = pre_ids.shape()[1];
    constexpr int BlockSize = 256;  // bsz <= 256
    const int max_decoder_block_num = length / block_size;
    // const int max_decoder_block_num = 2048 / block_size -
    // encoder_decoder_block_num;
#ifdef DEBUG_STEP
    printf(
        "bsz: %d, block_num_per_seq: %d, length: %d, max_decoder_block_num: "
        "%d\n",
        bsz,
        block_num_per_seq,
        length,
        max_decoder_block_num);
#endif
    speculate_free_and_dispatch_block<<<1, BlockSize, 0, cu_stream>>>(
        const_cast<bool *>(stop_flags.data<bool>()),
        const_cast<int *>(seq_lens_this_time.data<int>()),
        const_cast<int *>(seq_lens_decoder.data<int>()),
        const_cast<int *>(block_tables.data<int>()),
        const_cast<int *>(encoder_block_lens.data<int>()),
        const_cast<bool *>(is_block_step.data<bool>()),
        const_cast<int *>(step_block_list.data<int>()),
        const_cast<int *>(step_lens.data<int>()),
        const_cast<int *>(recover_block_list.data<int>()),
        const_cast<int *>(recover_lens.data<int>()),
        const_cast<int *>(need_block_list.data<int>()),
        const_cast<int *>(need_block_len.data<int>()),
        const_cast<int *>(used_list_len.data<int>()),
        const_cast<int *>(free_list.data<int>()),
        const_cast<int *>(free_list_len.data<int>()),
        const_cast<int64_t *>(first_token_ids.data<int64_t>()),
        const_cast<int *>(accept_num.data<int>()),
        bsz,
        block_size,
        block_num_per_seq,
        max_decoder_block_num,
        max_draft_tokens);
#ifdef DEBUG_STEP
    cudaDeviceSynchronize();
#endif
    auto cpu_recover_lens = recover_lens.copy_to(paddle::CPUPlace(), false);
    const int grid_size = cpu_recover_lens.data<int>()[0];
#ifdef DEBUG_STEP
    printf("grid_size2 %d\n", grid_size);
#endif
    if (grid_size > 0) {
        speculate_recover_block<<<grid_size, BlockSize, 0, cu_stream>>>(
            const_cast<int *>(recover_block_list.data<int>()),
            const_cast<int *>(recover_lens.data<int>()),
            const_cast<bool *>(stop_flags.data<bool>()),
            const_cast<int *>(seq_lens_this_time.data<int>()),
            const_cast<int *>(ori_seq_lens_encoder.data<int>()),
            const_cast<int *>(ori_seq_lens_decoder.data<int>()),
            const_cast<int *>(seq_lens_encoder.data<int>()),
            const_cast<int *>(seq_lens_decoder.data<int>()),
            const_cast<int *>(block_tables.data<int>()),
            const_cast<int *>(free_list.data<int>()),
            const_cast<int *>(free_list_len.data<int>()),
            const_cast<int64_t *>(input_ids.data<int64_t>()),
            const_cast<int64_t *>(pre_ids.data<int64_t>()),
            const_cast<int64_t *>(step_idx.data<int64_t>()),
            const_cast<int *>(encoder_block_lens.data<int>()),
            const_cast<int *>(used_list_len.data<int>()),
            next_tokens.data<int64_t>(),
            first_token_ids.data<int64_t>(),
            bsz,
            block_num_per_seq,
            length,
            pre_id_length);
#ifdef DEBUG_STEP
        cudaDeviceSynchronize();
#endif
    }
}

PD_BUILD_STATIC_OP(speculate_step_system_cache)
    .Inputs({"stop_flags",
             "seq_lens_this_time",
             "ori_seq_lens_encoder",
             "ori_seq_lens_decoder",
             "seq_lens_encoder",
             "seq_lens_decoder",
             "block_tables",
             "encoder_block_lens",
             "is_block_step",
             "step_block_list",
             "step_lens",
             "recover_block_list",
             "recover_lens",
             "need_block_list",
             "need_block_len",
             "used_list_len",
             "free_list",
             "free_list_len",
             "input_ids",
             "pre_ids",
             "step_idx",
             "next_tokens",
             "first_token_ids",
             "accept_num"})
    .Attrs({"block_size: int",
            "encoder_decoder_block_num: int",
            "max_draft_tokens: int"})
    .Outputs({"stop_flags_out",
              "seq_lens_this_time_out",
              "seq_lens_encoder_out",
              "seq_lens_decoder_out",
              "block_tables_out",
              "encoder_block_lens_out",
              "is_block_step_out",
              "step_block_list_out",
              "step_lens_out",
              "recover_block_list_out",
              "recover_lens_out",
              "need_block_list_out",
              "need_block_len_out",
              "used_list_len_out",
              "free_list_out",
              "free_list_len_out",
              "input_ids_out",
              "first_token_ids_out"})
    .SetInplaceMap({{"stop_flags", "stop_flags_out"},
                    {"seq_lens_this_time", "seq_lens_this_time_out"},
                    {"seq_lens_encoder", "seq_lens_encoder_out"},
                    {"seq_lens_decoder", "seq_lens_decoder_out"},
                    {"block_tables", "block_tables_out"},
                    {"encoder_block_lens", "encoder_block_lens_out"},
                    {"is_block_step", "is_block_step_out"},
                    {"step_block_list", "step_block_list_out"},
                    {"step_lens", "step_lens_out"},
                    {"recover_block_list", "recover_block_list_out"},
                    {"recover_lens", "recover_lens_out"},
                    {"need_block_list", "need_block_list_out"},
                    {"need_block_len", "need_block_len_out"},
                    {"used_list_len", "used_list_len_out"},
                    {"free_list", "free_list_out"},
                    {"free_list_len", "free_list_len_out"},
                    {"input_ids", "input_ids_out"},
                    {"first_token_ids", "first_token_ids_out"}})
    .SetKernelFn(PD_KERNEL(SpeculateStepPaddle));
